Pituitary and thyroid function in male cynomolgus monkeys.
In four male cynomolgus monkeys, serum thyroxine was 6.2 +/- 0.9 micrograms/dl, and triiodothyronine was 207 +/- 12 ng/dl (mean +/- SE). Kinetic studies using 131I-thyroxine and 125I-triiodothyronine showed that the disappearance of both hormones was non-linear and best fit a biexponential equation. The metabolic clearance rates and production rates for thyroxine were 21.5 +/- 0.6 ml/kg/day and 1.34 +/- 0.23 micrograms/kg/day, respectively, and T1/2(beta) = 29.6 +/- 2.0 hours. For triiodothyronine, the metabolic clearance rate was 156.6 +/- 12.0 ml/kg/day, the production rate was 0.33 +/- 0.04 micrograms/kg/day, and T1/2 (beta) was 13.3 +/- 1.3 hours. Basel serum thyrotropin levels in five euthyroid animals were 1.4 +/- 0.6 microU/ml and increased after thyrotropin-releasing hormone to 6.7 +/- 2.2 microU/ml. Serum prolactin was 5.8 +/- 0.7 ng/ml, and it increased to 26.6 +/- 4.5 ng/ml after thyrotropin-releasing hormone. Four animals received chronic dexamethasone therapy (1 mg twice daily for 5.5 months). While baseline and thyrotropin-releasing hormone stimulated thyrotropin values were lower (0.8 +/- 0.2 microU/ml and 3.2 +/- 0.5 microU/ml, respectively), these reductions were not significant.
D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology; D008251:Macaca / Q000502:physiology*; D008252:Macaca fascicularis / Q000502:physiology*; D008297:Male; D008657:Metabolic Clearance Rate; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011388:Prolactin / Q000097:blood; D013961:Thyroid Gland / Q000378:metabolism*; D013972:Thyrotropin / Q000097:blood; D013973:Thyrotropin-Releasing Hormone; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D014284:Triiodothyronine; D013973:Thyrotropin-Releasing Hormone; D003907:Dexamethasone; D011388:Prolactin; D013972:Thyrotropin; D013974:Thyroxine